terraform/plans/planfile/tfplan.go

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package planfile
import (
"fmt"
"io"
"io/ioutil"
2020-12-01 22:07:05 +01:00
"google.golang.org/protobuf/proto"
"github.com/hashicorp/terraform/addrs"
"github.com/hashicorp/terraform/plans"
"github.com/hashicorp/terraform/plans/internal/planproto"
"github.com/hashicorp/terraform/states"
"github.com/hashicorp/terraform/tfdiags"
"github.com/hashicorp/terraform/version"
)
const tfplanFormatVersion = 3
const tfplanFilename = "tfplan"
// ---------------------------------------------------------------------------
// This file deals with the internal structure of the "tfplan" sub-file within
// the plan file format. It's all private API, wrapped by methods defined
// elsewhere. This is the only file that should import the
// ../internal/planproto package, which contains the ugly stubs generated
// by the protobuf compiler.
// ---------------------------------------------------------------------------
// readTfplan reads a protobuf-encoded description from the plan portion of
// a plan file, which is stored in a special file in the archive called
// "tfplan".
func readTfplan(r io.Reader) (*plans.Plan, error) {
src, err := ioutil.ReadAll(r)
if err != nil {
return nil, err
}
var rawPlan planproto.Plan
err = proto.Unmarshal(src, &rawPlan)
if err != nil {
return nil, fmt.Errorf("parse error: %s", err)
}
if rawPlan.Version != tfplanFormatVersion {
return nil, fmt.Errorf("unsupported plan file format version %d; only version %d is supported", rawPlan.Version, tfplanFormatVersion)
}
if rawPlan.TerraformVersion != version.String() {
return nil, fmt.Errorf("plan file was created by Terraform %s, but this is %s; plan files cannot be transferred between different Terraform versions", rawPlan.TerraformVersion, version.String())
}
plan := &plans.Plan{
VariableValues: map[string]plans.DynamicValue{},
Changes: &plans.Changes{
Outputs: []*plans.OutputChangeSrc{},
Resources: []*plans.ResourceInstanceChangeSrc{},
},
ProviderSHA256s: map[string][]byte{},
}
for _, rawOC := range rawPlan.OutputChanges {
name := rawOC.Name
change, err := changeFromTfplan(rawOC.Change)
if err != nil {
return nil, fmt.Errorf("invalid plan for output %q: %s", name, err)
}
plan.Changes.Outputs = append(plan.Changes.Outputs, &plans.OutputChangeSrc{
// All output values saved in the plan file are root module outputs,
// since we don't retain others. (They can be easily recomputed
// during apply).
Addr: addrs.OutputValue{Name: name}.Absolute(addrs.RootModuleInstance),
ChangeSrc: *change,
Sensitive: rawOC.Sensitive,
})
}
for _, rawRC := range rawPlan.ResourceChanges {
change, err := resourceChangeFromTfplan(rawRC)
if err != nil {
// errors from resourceChangeFromTfplan already include context
return nil, err
}
plan.Changes.Resources = append(plan.Changes.Resources, change)
}
for _, rawTargetAddr := range rawPlan.TargetAddrs {
target, diags := addrs.ParseTargetStr(rawTargetAddr)
if diags.HasErrors() {
return nil, fmt.Errorf("plan contains invalid target address %q: %s", target, diags.Err())
}
plan.TargetAddrs = append(plan.TargetAddrs, target.Subject)
}
for name, rawHashObj := range rawPlan.ProviderHashes {
if len(rawHashObj.Sha256) == 0 {
return nil, fmt.Errorf("no SHA256 hash for provider %q plugin", name)
}
plan.ProviderSHA256s[name] = rawHashObj.Sha256
}
for name, rawVal := range rawPlan.Variables {
val, err := valueFromTfplan(rawVal)
if err != nil {
return nil, fmt.Errorf("invalid value for input variable %q: %s", name, err)
}
plan.VariableValues[name] = val
}
if rawBackend := rawPlan.Backend; rawBackend == nil {
return nil, fmt.Errorf("plan file has no backend settings; backend settings are required")
} else {
config, err := valueFromTfplan(rawBackend.Config)
if err != nil {
return nil, fmt.Errorf("plan file has invalid backend configuration: %s", err)
}
plan.Backend = plans.Backend{
Type: rawBackend.Type,
Config: config,
Workspace: rawBackend.Workspace,
}
}
return plan, nil
}
func resourceChangeFromTfplan(rawChange *planproto.ResourceInstanceChange) (*plans.ResourceInstanceChangeSrc, error) {
if rawChange == nil {
// Should never happen in practice, since protobuf can't represent
// a nil value in a list.
return nil, fmt.Errorf("resource change object is absent")
}
ret := &plans.ResourceInstanceChangeSrc{}
moduleAddr := addrs.RootModuleInstance
if rawChange.ModulePath != "" {
var diags tfdiags.Diagnostics
moduleAddr, diags = addrs.ParseModuleInstanceStr(rawChange.ModulePath)
if diags.HasErrors() {
return nil, diags.Err()
}
}
providerAddr, diags := addrs.ParseAbsProviderConfigStr(rawChange.Provider)
if diags.HasErrors() {
return nil, diags.Err()
}
ret.ProviderAddr = providerAddr
var mode addrs.ResourceMode
switch rawChange.Mode {
case planproto.ResourceInstanceChange_managed:
mode = addrs.ManagedResourceMode
case planproto.ResourceInstanceChange_data:
mode = addrs.DataResourceMode
default:
return nil, fmt.Errorf("resource has invalid mode %s", rawChange.Mode)
}
typeName := rawChange.Type
name := rawChange.Name
resAddr := addrs.Resource{
Mode: mode,
Type: typeName,
Name: name,
}
var instKey addrs.InstanceKey
switch rawTk := rawChange.InstanceKey.(type) {
case nil:
case *planproto.ResourceInstanceChange_Int:
instKey = addrs.IntKey(rawTk.Int)
case *planproto.ResourceInstanceChange_Str:
instKey = addrs.StringKey(rawTk.Str)
default:
return nil, fmt.Errorf("instance of %s has invalid key type %T", resAddr.Absolute(moduleAddr), rawChange.InstanceKey)
}
ret.Addr = resAddr.Instance(instKey).Absolute(moduleAddr)
if rawChange.DeposedKey != "" {
if len(rawChange.DeposedKey) != 8 {
return nil, fmt.Errorf("deposed object for %s has invalid deposed key %q", ret.Addr, rawChange.DeposedKey)
}
ret.DeposedKey = states.DeposedKey(rawChange.DeposedKey)
}
change, err := changeFromTfplan(rawChange.Change)
if err != nil {
return nil, fmt.Errorf("invalid plan for resource %s: %s", ret.Addr, err)
}
ret.ChangeSrc = *change
if len(rawChange.Private) != 0 {
ret.Private = rawChange.Private
}
return ret, nil
}
func changeFromTfplan(rawChange *planproto.Change) (*plans.ChangeSrc, error) {
if rawChange == nil {
return nil, fmt.Errorf("change object is absent")
}
ret := &plans.ChangeSrc{}
// -1 indicates that there is no index. We'll customize these below
// depending on the change action, and then decode.
beforeIdx, afterIdx := -1, -1
switch rawChange.Action {
case planproto.Action_NOOP:
ret.Action = plans.NoOp
beforeIdx = 0
afterIdx = 0
case planproto.Action_CREATE:
ret.Action = plans.Create
afterIdx = 0
case planproto.Action_READ:
ret.Action = plans.Read
beforeIdx = 0
afterIdx = 1
case planproto.Action_UPDATE:
ret.Action = plans.Update
beforeIdx = 0
afterIdx = 1
case planproto.Action_DELETE:
ret.Action = plans.Delete
beforeIdx = 0
case planproto.Action_CREATE_THEN_DELETE:
ret.Action = plans.CreateThenDelete
beforeIdx = 0
afterIdx = 1
case planproto.Action_DELETE_THEN_CREATE:
ret.Action = plans.DeleteThenCreate
beforeIdx = 0
afterIdx = 1
default:
return nil, fmt.Errorf("invalid change action %s", rawChange.Action)
}
if beforeIdx != -1 {
if l := len(rawChange.Values); l <= beforeIdx {
return nil, fmt.Errorf("incorrect number of values (%d) for %s change", l, rawChange.Action)
}
var err error
ret.Before, err = valueFromTfplan(rawChange.Values[beforeIdx])
if err != nil {
return nil, fmt.Errorf("invalid \"before\" value: %s", err)
}
if ret.Before == nil {
return nil, fmt.Errorf("missing \"before\" value: %s", err)
}
}
if afterIdx != -1 {
if l := len(rawChange.Values); l <= afterIdx {
return nil, fmt.Errorf("incorrect number of values (%d) for %s change", l, rawChange.Action)
}
var err error
ret.After, err = valueFromTfplan(rawChange.Values[afterIdx])
if err != nil {
return nil, fmt.Errorf("invalid \"after\" value: %s", err)
}
if ret.After == nil {
return nil, fmt.Errorf("missing \"after\" value: %s", err)
}
}
return ret, nil
}
func valueFromTfplan(rawV *planproto.DynamicValue) (plans.DynamicValue, error) {
if len(rawV.Msgpack) == 0 { // len(0) because that's the default value for a "bytes" in protobuf
return nil, fmt.Errorf("dynamic value does not have msgpack serialization")
}
return plans.DynamicValue(rawV.Msgpack), nil
}
// writeTfplan serializes the given plan into the protobuf-based format used
// for the "tfplan" portion of a plan file.
func writeTfplan(plan *plans.Plan, w io.Writer) error {
if plan == nil {
return fmt.Errorf("cannot write plan file for nil plan")
}
if plan.Changes == nil {
return fmt.Errorf("cannot write plan file with nil changeset")
}
rawPlan := &planproto.Plan{
Version: tfplanFormatVersion,
TerraformVersion: version.String(),
ProviderHashes: map[string]*planproto.Hash{},
Variables: map[string]*planproto.DynamicValue{},
OutputChanges: []*planproto.OutputChange{},
ResourceChanges: []*planproto.ResourceInstanceChange{},
}
for _, oc := range plan.Changes.Outputs {
// When serializing a plan we only retain the root outputs, since
// changes to these are externally-visible side effects (e.g. via
// terraform_remote_state).
if !oc.Addr.Module.IsRoot() {
continue
}
name := oc.Addr.OutputValue.Name
// Writing outputs as cty.DynamicPseudoType forces the stored values
// to also contain dynamic type information, so we can recover the
// original type when we read the values back in readTFPlan.
protoChange, err := changeToTfplan(&oc.ChangeSrc)
if err != nil {
return fmt.Errorf("cannot write output value %q: %s", name, err)
}
rawPlan.OutputChanges = append(rawPlan.OutputChanges, &planproto.OutputChange{
Name: name,
Change: protoChange,
Sensitive: oc.Sensitive,
})
}
for _, rc := range plan.Changes.Resources {
rawRC, err := resourceChangeToTfplan(rc)
if err != nil {
return err
}
rawPlan.ResourceChanges = append(rawPlan.ResourceChanges, rawRC)
}
for _, targetAddr := range plan.TargetAddrs {
rawPlan.TargetAddrs = append(rawPlan.TargetAddrs, targetAddr.String())
}
for name, hash := range plan.ProviderSHA256s {
rawPlan.ProviderHashes[name] = &planproto.Hash{
Sha256: hash,
}
}
for name, val := range plan.VariableValues {
rawPlan.Variables[name] = valueToTfplan(val)
}
if plan.Backend.Type == "" || plan.Backend.Config == nil {
// This suggests a bug in the code that created the plan, since it
// ought to always have a backend populated, even if it's the default
// "local" backend with a local state file.
return fmt.Errorf("plan does not have a backend configuration")
}
rawPlan.Backend = &planproto.Backend{
Type: plan.Backend.Type,
Config: valueToTfplan(plan.Backend.Config),
Workspace: plan.Backend.Workspace,
}
src, err := proto.Marshal(rawPlan)
if err != nil {
return fmt.Errorf("serialization error: %s", err)
}
_, err = w.Write(src)
if err != nil {
return fmt.Errorf("failed to write plan to plan file: %s", err)
}
return nil
}
func resourceChangeToTfplan(change *plans.ResourceInstanceChangeSrc) (*planproto.ResourceInstanceChange, error) {
ret := &planproto.ResourceInstanceChange{}
ret.ModulePath = change.Addr.Module.String()
relAddr := change.Addr.Resource
switch relAddr.Resource.Mode {
case addrs.ManagedResourceMode:
ret.Mode = planproto.ResourceInstanceChange_managed
case addrs.DataResourceMode:
ret.Mode = planproto.ResourceInstanceChange_data
default:
return nil, fmt.Errorf("resource %s has unsupported mode %s", relAddr, relAddr.Resource.Mode)
}
ret.Type = relAddr.Resource.Type
ret.Name = relAddr.Resource.Name
switch tk := relAddr.Key.(type) {
case nil:
// Nothing to do, then.
case addrs.IntKey:
ret.InstanceKey = &planproto.ResourceInstanceChange_Int{
Int: int64(tk),
}
case addrs.StringKey:
ret.InstanceKey = &planproto.ResourceInstanceChange_Str{
Str: string(tk),
}
default:
return nil, fmt.Errorf("resource %s has unsupported instance key type %T", relAddr, relAddr.Key)
}
ret.DeposedKey = string(change.DeposedKey)
ret.Provider = change.ProviderAddr.String()
valChange, err := changeToTfplan(&change.ChangeSrc)
if err != nil {
return nil, fmt.Errorf("failed to serialize resource %s change: %s", relAddr, err)
}
ret.Change = valChange
if len(change.Private) > 0 {
ret.Private = change.Private
}
return ret, nil
}
func changeToTfplan(change *plans.ChangeSrc) (*planproto.Change, error) {
ret := &planproto.Change{}
before := valueToTfplan(change.Before)
after := valueToTfplan(change.After)
switch change.Action {
case plans.NoOp:
ret.Action = planproto.Action_NOOP
ret.Values = []*planproto.DynamicValue{before} // before and after should be identical
case plans.Create:
ret.Action = planproto.Action_CREATE
ret.Values = []*planproto.DynamicValue{after}
case plans.Read:
ret.Action = planproto.Action_READ
ret.Values = []*planproto.DynamicValue{before, after}
case plans.Update:
ret.Action = planproto.Action_UPDATE
ret.Values = []*planproto.DynamicValue{before, after}
case plans.Delete:
ret.Action = planproto.Action_DELETE
ret.Values = []*planproto.DynamicValue{before}
case plans.DeleteThenCreate:
ret.Action = planproto.Action_DELETE_THEN_CREATE
ret.Values = []*planproto.DynamicValue{before, after}
case plans.CreateThenDelete:
ret.Action = planproto.Action_CREATE_THEN_DELETE
ret.Values = []*planproto.DynamicValue{before, after}
default:
return nil, fmt.Errorf("invalid change action %s", change.Action)
}
return ret, nil
}
func valueToTfplan(val plans.DynamicValue) *planproto.DynamicValue {
if val == nil {
// protobuf can't represent nil, so we'll represent it as a
// DynamicValue that has no serializations at all.
return &planproto.DynamicValue{}
}
return &planproto.DynamicValue{
Msgpack: []byte(val),
}
}